Mold for blow molding, method for manufacturing resin container using same, and resin container

ABSTRACT

A blow molding mold in which a holding mechanism is independently provided to a bottom mold and is configured to be capable of gripping a protruding portion provided to a bottom portion of a preform independently of a gate portion, and a rotation mechanism is configured to be capable of rotating the bottom mold, relative to a neck portion of the preform which is in a stationary state held by neck molds, in a state where the protruding portion is gripped by the holding mechanism.

TECHNICAL FIELD

The present invention relates to a blow molding mold, a method formanufacturing a resin container using the same, and a container made ofresin.

BACKGROUND ART

Patent Literature 1, Patent Literature 2 and Patent Literature 3disclose a stretch blow molding method. Patent Literature 4 discloses adirect blow molding method.

CITATION LIST Patent Literature

[Patent Literature 1] JP-A-2006-062110

[Patent Literature 2] Japanese Patent No. 5,103,247

[Patent Literature 3] Japanese Patent No. 3,893,054

[Patent Literature 4] Japanese Patent No. 4,093,562

SUMMARY OF INVENTION Technical Problem

Examples of a container that is manufactured by blow molding include acontainer with a bent neck where a central axis of a neck portion isinclined relative to a central axis of a body portion. A container wherean inclination angle of a neck portion is small can also be manufacturedby stretch blow molding by using an inclination stretch mechanismdisclosed in Patent Literature 1, Patent Literature 2 and PatentLiterature 3. However, since a container in which an inclination angleof a neck portion is large (for example, 60° or larger) is substantiallyimpossible to be manufactured by the inclination stretch mechanism, suchcontainer is manufactured by the direct blow molding disclosed in PatentLiterature 4.

On the other hand, the container that can be manufactured by the directblow molding is generally inferior to the container manufactured by thestretch blow molding in terms of aesthetic appearance. There is anincreasing desire to manufacture a container with a bent neck having alarge inclination angle by the stretch blow molding.

It is therefore an object of the present invention to provide a blowmolding mold capable of manufacturing a container with a bent neckhaving a large inclination angle by stretch blow molding, a method formanufacturing a resin container using the same, and a container made ofresin.

Solution to Problem

A blow molding mold of the present invention capable of achieving theabove object is a blow molding mold including:

a bottom mold;

a neck mold;

a holding mechanism; and

a rotation mechanism,

in which the holding mechanism is independently provided to the bottommold and is configured to be capable of gripping a protruding portionprovided to a bottom portion of a preform independently of a gateportion, and

the rotation mechanism is configured to be capable of rotating thebottom mold, relative to a neck portion of the preform in a stationarystate held by the neck mold, in a state where the protruding portion isgripped by the holding mechanism.

According to the blow molding mold configured as described above, it ispossible to manufacture a container with a bent neck having a largeinclination angle by stretch blow molding.

A method for manufacturing a resin container according to the presentinvention includes:

a holding process of gripping a protruding portion, which is provided toa bottom portion of a preform accommodated in a blow molding moldindependently of a gate portion, by a holding mechanism independentlyprovided to a bottom mold of the blow molding mold, in a state wheresplit molds of the blow molding mold are opened;

a bending process of bending the preform by rotating the bottom moldwhich is gripping the protruding portion relative to a neck portion ofthe preform which is in a stationary state held by a neck mold; and

a blowing process of closing the split molds and stretching the preformby a pressurizing medium.

According to the blow molding method of a resin container configured asdescribed above, it is possible to manufacture a container with a bentneck having a large inclination angle by a method other than direct blowmolding.

It is preferable that the method for manufacturing a resin containeraccording to the present invention includes a preliminary stretchingprocess of stretching the bottom portion of the preform toward thebottom mold by a stretch rod before the holding process.

According to the blow molding method of a resin container configured asdescribed above, it is possible to manufacture a container with a bentneck having a large inclination angle by stretch blow molding.

A container of the present invention is a container made of resin,including:

a neck portion having an opening;

a body portion formed to be continuous to the neck portion and defininga sidewall part; and

a bottom portion formed to be continuous to the body portion,

in which an inclination angle between an axis passing through a centerof the opening and orthogonal to an opening surface formed by theopening and an axis extending in

a vertical direction of the container is equal to or larger than 50° andequal to or smaller than 80°, and

when a direction extending in a horizontal diametrical direction of theopening is referred to as a width direction of the container and adirection in which an axis orthogonal to the opening surface formed bythe opening extends is referred to as a depth direction of thecontainer, a length in the width direction and a length in the depthdirection of a horizontal section of the body portion are different fromeach other.

In the container, it is preferable that:

the bottom portion includes a projecting portion projecting outward froman outer surface of the bottom portion.

In the container, it is preferable that:

the body portion includes an upper body portion having an inclinedsurface portion inclined along a direction orthogonal to the axisorthogonal to the opening surface formed by the opening, and a lowerbody portion connected to the upper body portion and extending in thevertical direction,

horizontal sections of the upper body portion and the lower body portionhave polygonal shapes, and

a number of corners of the polygonal shape of the horizontal section ofthe upper body portion is smaller than a number of corners of thepolygonal shape of the horizontal section of the lower body portion.

Advantageous Effects of Invention

According to the present invention, it is possible to provide the blowmolding mold capable of manufacturing a container with a bent neckhaving a large inclination angle by the stretch blow molding, the methodfor manufacturing a resin container using the same, and a container madeof resin.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 depicts a container with a bent neck having a large inclinationangle, in which (a) is a left side view of the container and (b) is afront view of the container.

FIG. 2 is a functional block diagram of a blow molding device.

FIG. 3 depicts an outer shape of a preform, in which (a) is a front viewof the preform, (b) is a left side view of the preform, (c) is apartially enlarged front view of the preform, and (d) is a partiallyenlarged left side view of the preform.

FIG. 4 depicts a blow molding mold, in which (a) is a front view of themold, and (b) is a left side view of the mold.

FIG. 5 depicts a holding mechanism.

FIG. 6 depicts an aspect of blow molding, in which (a) depicts an aspectwhere a preform is accommodated in a mold in a state where split molds(not shown) are opened, (b) depicts a state where a protruding portionof the preform is gripped by the holding mechanism, and (c) depicts astate where the preform is bent.

FIG. 7 depicts an aspect of a container with a bent neck having a largeinclination angle, in which (a) depicts the container, as seen from anopening-side, (b) depicts a front appearance of the container, (c)depicts a right side appearance of the container, (d) is a sectionalview of the container taken along a line E-E, and (e) is a sectionalview of the container taken along a line F-F.

DESCRIPTION OF EMBODIMENTS

Hereinbelow, embodiments of the present invention will be described withreference to the drawings. Note that, the sizes of the members shown inthe drawings may be different from the sizes of the actual members, forconvenience of descriptions.

First, a container 10 with a bent neck of the present embodiment isdescribed with reference to FIG. 1. (a) of FIG. 1 is a left side view ofthe container 10, and (b) of FIG. 1 is a front view of the container 10.The container 10 is a container made of resin and includes a neckportion 12 having an opening 11, a body portion 13 formed to becontinuous to the neck portion 12 and defining a sidewall part of thecontainer 10, and a bottom portion 14 formed to be continuous to thebody portion 13. The bottom portion 14 has an outer edge portion formedto have a horizontal surface shape and serving as a ground contactingsurface, and an upper bottom portion depressed toward the body portion13 and forming a concave portion. An outer surface of the bottom portion14 (upper bottom portion) is provided with a projecting portion(projection trace portion) 215 (not shown) within a range of a depth ofthe depression of the bottom portion 14 (a depth of the upper bottomportion). In the present embodiment, an angle between an axis A passingthrough a center of the opening 11 of the neck portion 12 and orthogonalto an opening surface and an axis B extending in a vertical direction ofthe container 10 is referred to as an inclination angle X. In thepresent example, the inclination angle X of the container 10 is large,for example, substantially 60°. When bisecting the body portion 13 inthe vertical direction, an upper portion is substantially triangular ina front view ((b) of FIG. 1). A part of the body portion 13 connected tothe neck portion 12 at an upper position in the vertical direction isbent, and a part of the body portion 13 connected to the neck portion 12at a lower position in the vertical direction extends parallel to theopening surface ((b) of FIG. 1). Note that, a traverse section in thehorizontal direction of the body portion 13 may have any shape among aflat shape, a substantially elliptical shape, a substantially truecircular shape, and a polygonal shape (a flat shape, in the container 10of FIG. 1). In the present example, a height of the container 10 isabout 13 cm, a width is about 3 cm, and a depth is about 4 cm. Notethat, in the container 10 and a container 10A to be described later, thewidth indicates a length in a minor axis direction (minor radiusdirection) of the horizontal cross section of the body portion 13 or thebottom portion 14, and the depth indicates a length in a major axisdirection (minor radius direction) of the horizontal cross section ofthe body portion 13 or the bottom portion 14.

Subsequently, a blow molding device 100 for manufacturing a container isdescribed with reference to FIG. 2. FIG. 2 is a block diagram of theblow molding device 100.

As shown in FIG. 2, the blow molding device 100 includes an injectionmolding part 110 for manufacturing a preform 20, and a temperatureadjustment part 120 for adjusting a temperature of the manufacturedpreform 20. The injection molding part 110 is connected to an injectiondevice 112 configured to supply a resin material that is a raw material.A synthetic resin that is a raw material is a thermoplastic resin, andcan be selected as appropriate depending on uses. Examples of thesynthetic resin include PET (polyethylene terephthalate), PEN(polyethylene naphthalate), PCTA (polycyclohexanedimethyleneterephthalate), Tritan (tritan: copolyester), PP (polypropylene), PE(polyethylene), PC (polycarbonate), PES (polyether sulfone), PPUS(polyphenyl sulfone), PS (polystyrene), COP/COC (cyclic olefin polymer),PMMA (polymethylmethacrylate: acrylic), PLA (polylactic acid), and thelike. Biodegradable plastics can also be used. The blow molding device100 also includes a blow molding part 130 for blowing the preform 20 tomanufacture the container 10, and a take-out part 140 for taking out themanufactured container 10.

The injection molding part 110, the temperature adjustment part 120, theblow molding part 130 and the take-out part 140 are provided atpositions rotated by predetermined angles (in the present embodiment,90°) about a conveying means 150. The conveying means 150 includes arotation plate and the like, and is configured such that the preform 20or the container 10 in a state where the neck portion 22 or 12 issupported by neck molds 152 attached to the rotation plate is conveyedto each part as the rotation plate is rotated, as shown in FIGS. 4 and6.

The injection molding part 110 shown in FIG. 2 has an injection cavitymold, an injection core mold, a neck mold and the like, which are notshown. By causing the resin material to flow from the injection device112 into a preform-shaped space formed by mold-clamping the molds, abottomed preform 20 is manufactured.

The preform 20 of the present embodiment is described with reference toFIG. 3. (a) of FIG. 3 is a front view of the preform 20, (b) of FIG. 3is a right side view of the preform 20, (c) of FIG. 3 is a partiallyenlarged front view of the preform 20, and (d) of FIG. 3 is a partiallyenlarged right side view of the preform 20. The preform 20 includes aneck portion 22 having an opening 21, a body portion 23 formed to becontinuous to the neck portion 22 and defining a sidewall part of thepreform 20, and a bottom portion 24 formed to be continuous to the bodyportion 23. A central portion of the bottom portion 24 is provided witha projecting portion 25. The projecting portion 25 includes a gateportion 26 close to an injection gate for a resin during preformmolding, and a protruding portion 27 formed on a further upper side thanthe gate portion 26 in the vertical direction and continuous to a lowerend of the preform 20. The protruding portion 27 has a flat shape, adiameter thereof is larger than (a width thereof is larger than) that ofthe gate portion 26 in a front view ((a) and (c) of FIG. 3), and a widththereof is equivalent to that of the gate portion 26 in a side view ((b)and (d) of FIG. 3). That is, a length of the protruding portion 27 in aright and left direction (a right and left direction on the drawingsheet of (a) and (b) of FIG. 3; a wide width direction in which theprotruding portion 27 is seen wider than the gate portion 26 in a statewhere the preform 20 is supported by the neck molds 152) is longer thana length of the gate portion 26 in the right and left direction on thedrawing sheet of (a) and (b) of FIG. 3. A length of the protrudingportion 27 in a front and rear direction (a right and left direction onthe drawing sheet of (b) and (d) of FIG. 3; a direction in which a widthof the protruding portion 27 is seen equal to a width of the gateportion 26 in a state where the preform 20 is supported by the neckmolds 152) is equivalent to a length of the gate portion 26 in the frontand rear direction.

Returning to FIG. 2, the blow molding device 100 is described. Thetemperature adjustment part 120 is configured to adjust a temperature ofthe preform 20 manufactured in the injection molding part 110 to atemperature suitable for final blow. The blow molding part 130 isconfigured to perform blow molding on the preform 20 whose temperaturehas been adjusted by the temperature adjustment part 120, therebymanufacturing the container 10 made of resin. The blow molding part 130has a blow molding mold 200 and a stretch rod 132.

Here, the blow molding mold 200 of the blow molding part 130 isdescribed in detail with reference to FIG. 4. (a) of FIG. 4 is a frontview of the mold 200, and (b) of FIG. 4 is a left side view of the mold200. The mold 200 has a pair of split molds (blow cavity split molds)210, a bottom mold 220, a pair of neck molds 152, a holding mechanism230, and a rotation mechanism 240.

The split molds 210 are configured to open and close in the right andleft direction (opening and closing direction D), based on partingsurfaces C, in a side view ((b) of FIG. 4). The pair of left and rightsplit molds 210 configures a space S for defining the body portion 13 ofthe container 10, in a closed state.

The bottom mold 220 includes a first bottom mold member 221 configuredto define the bottom portion 14 of the container 10, and a second bottommold member (accommodation block) 260 arranged below the first bottommold member 221. In the bottom mold 220, the holding mechanism 230 isprovided so as to be accommodated therein ((a) and (b) of FIG. 4). Inthe first bottom mold member 221, at least a part of a holding portion232 (which will be described later) of the holding mechanism 230 isaccommodated, and in the second bottom mold member 260, at least a partof an opening and closing mechanism 234 (which will be described later)of the holding mechanism 230 is accommodated. The second bottom moldmember 260 is provided on an upper surface of a guided part 244, whichwill be described later. The bottom mold 220 and the guided part 244(which will be described later) are integrally configured to be movablealong a guide part 242 (which will be described later).

Here, the holding mechanism 230 is described with reference to FIG. 5.The holding mechanism 230 has a holding portion 232 configured to becapable of gripping the protruding portion 27 of the projecting portion25 provided to the bottom portion 24 of the preform 20. The holdingportion 232 is provided independently from the bottom mold 220(separately provided without being directly provided to the bottom mold220). The holding portion 232 is configured to be openable and closableby a drive member (opening and closing mechanism 234) connected via alink mechanism at the lower part of the bottom mold 220, and holds theprotruding portion 27 by changing from an opened state to a closedstate. A tip end of the holding portion 232 is provided with a clawportion 233 protruding inward from the holding portion 232, and the clawportion 233 is configured to bite the protruding portion 27 in a statewhere the holding portion 232 is closed.

The first bottom mold member 221 includes a first accommodation part236A. The second bottom mold member 260 includes a second accommodationpart 236B. As used herein, a part having the first accommodation part236A and the second accommodation part 236B is defined as anaccommodation part 236. Note that, the first accommodation part 236A andthe second accommodation part 236B communicate with each other. Theaccommodation block 260 and the bottom mold 220 are each provided withan opening portion for guiding the projecting portion 25 of the preform20 to the holding portion 232. The holding portion 232 and the openingand closing mechanism 234 are covered by the accommodation part 236. Inthe accommodation part 236, the holding mechanism 230 is arranged.

Returning to FIG. 4, the mold 200 is described. As described above, thepreform 20 or the container 10 is conveyed to each part as the rotationplate is rotated, in a state where the neck molds 152 are attached tothe rotation plate and support the neck portion 12, 22. The rotationmechanism 240 has a guide part 242 arranged on a side of the bottom mold220 and below the split molds 210 and having a flat shape and a camgroove 243, and a guided part (cam follower) 244 connected to a movingblock (not shown) fixed just below the accommodation part 236 ((a) ofFIG. 4). The cam groove 243 of the guide part 242 has at least a curvedportion, and is provided with a linear portion, as required. The curvedportion has one end portion in the vertical direction below the preform20 conveyed from the temperature adjustment part 120 by the rotationplate. The guided part 244 is moved along the curved portion, so thatthe body portion 23 and the bottom portion 24 of the preform 20 arerotated relative to the neck portion 22 by a predetermined angle (forexample, 60°) corresponding to the inclination angle X of the container10. Note that, during this operation, the neck portion 22 is immovablysupported by the neck molds and the like.

The rotation mechanism 240 is configured to be capable of moving theguided part 244 along the cam groove 243 of the guide part 242, therebyrotating the bottom mold 220 relative to positions at which the neckmolds 152 are arranged during blow molding, via the moving block. Thatis, the rotation mechanism 240 is configured to be capable of rotatingthe bottom mold 220, relative to the neck portion 22 of the preform 20in a stationary state held by the neck molds 152, in a state where theprotruding portion 27 is gripped by the holding mechanism 230. Therotation mechanism 240 is also configured to be capable of rotating thebottom mold 220 on a plane orthogonal to the opening and closingdirection D of the split molds 210 of the mold 200. In other words, therotation mechanism 240 is configured to be capable of rotating thebottom mold 220 along the parting surfaces C of the split molds 210.That is, the bottom mold 220 is moved from a first positioncorresponding to a central axis direction of the body portion 23 of thepreform 20 which is not bent (is straight), to a second positioncorresponding to a central axis direction of the body portion 23 of thepreform 20 which is bent (curved). Note that, the rotation mechanism 240can also be referred to as a swing mechanism or an oscillationmechanism.

Again back to FIG. 2, the take-out part 140 of the blow molding device100 is described. The take-out part 140 is configured to take out thecontainer 10 by removing the neck portion 12 of the container 10manufactured in the blow molding part 130 from the neck molds 152.

Subsequently, a blow molding method of the container 10 in the blowmolding part 130 of the blow molding device 100 is described withreference to FIG. 6. (a) of FIG. 6 depicts an aspect where the preform20 is accommodated in the mold 200 in a state where the split molds 210(not shown) are opened, (b) of FIG. 6 depicts a state where theprotruding portion 27 of the preform 20 is gripped by the holdingmechanism 230, and (c) of FIG. 6 depicts a state where the preform 20 isbent. In the present embodiment, the blow molding process includes aholding process of gripping the protruding portion 27 of the preform 20accommodated in the mold 200 by the holding mechanism 230 of the mold200, in a state where the split molds 210 of the mold 200 are opened; abending process of bending the preform 20 by rotating the bottom mold220 which is gripping the protruding portion 27 relative to the neckportion 22 of the preform 20 which is in a stationary state held by theneck molds 152; and a blowing process of closing the split molds 210 andstretching the preform 20 by a pressurizing medium.

First, the preform 20 supported by the neck molds 152 and adjusted to atemperature suitable for blow molding in the temperature adjustment part120 is conveyed to the blow molding part 130 by the conveying means 150and is accommodated in the mold 200 in a state where the split molds 210are opened ((a) of FIG. 6). Then, the stretch rod 132 provided to theblow molding part 130 and located at a standby position is moved down topress the bottom portion 24 of the preform 20 from an inside thereof,thereby stretching the preform 20 toward the bottom mold 220(preliminary stretching process). The preform 20 is stretched to thebottom mold 220, so that the projecting portion 25 of the bottom portion24 is accommodated in the opening portions of the bottom mold 220 andthe accommodation part 236 ((b) of FIG. 6). The protruding portion 27 ofthe accommodated projecting portion 25 is gripped by the holdingmechanism 230, and the bottom mold 220 of the mold 200 and the bottomportion 24 of the preform 20 are connected to each other (holdingprocess). Thereafter, the stretch rod 132 is moved up to the standbyposition.

Subsequently, the guided part 244 attached to the bottom mold 220 ismoved obliquely in an upper left direction in (b) of FIG. 6 along thecam groove 243 of the guide part 242 by the rotation mechanism 240.Thereby, the bottom mold 220 gripping the protruding portion 27 isrotated relative to the neck portion 22 of the preform 20 in astationary state held by the neck molds 152 ((c) of FIG. 6). Thereby, apart of the body portion 23 close to the neck portion 22 of the preform20 is bent (bending process). Then, the split molds 210 are closed toaccommodate the bent preform 20 in the space S defining an outer shapeof the container 10 configured by the neck molds 152, the split molds210 and the bottom mold 220. In this state, the pressurizing medium suchas air is introduced into the preform 20 to blow and stretch the preform20, so that the container 10 is molded (blowing process). After themolding, the split molds 210 are opened to release the container 10, andthe container 10 is conveyed to the take-out part 140 by the conveyingmeans 150. By the above method, it is possible to form the container 10with a bent neck from the preform 20 by blow molding.

In the meantime, a container where an inclination angle of a neckportion is small can also be manufactured by the stretch blow moldingusing the inclination stretch mechanism disclosed in Patent Literature1, Patent Literature 2 and Patent Literature 3. However, in theinclination stretch mechanism, it is necessary to bring a tip end of astretch rod into contact with an inner wall surface of a bottom portionof a preform before introduction of blow air. Therefore, since it issubstantially impossible for a container where an inclination angle of aneck portion is large (for example, 60° or larger) to satisfy thecondition, such container is manufactured by the direct blow molding.

On the other hand, the container that can be manufactured by the directblow molding is generally inferior to the container manufactured by thestretch blow molding in terms of aesthetic appearance. In addition,there are concerns such as poor welding (pinholes) at a pinch-offportion of the bottom portion of the container, dimensional accuracy ofthe neck portion is not high (airtightness is not good) because the neckportion of the container is also shaped by air blow, burrs should beremoved and an amount of useless resin (loss material) is large, apost-process referred to as trimming on a cut surface is necessary evenafter blow molding, and a container with high surface gloss is difficultto be manufactured.

The blow molding mold 200 according to the embodiment includes theholding mechanism 230 independently provided to the bottom mold 220 andconfigured to be capable of gripping the protruding portion 27 providedto the bottom portion 24 of the preform 20 independently of the gateportion 26, and the rotation mechanism 240 configured to be capable ofrotating the bottom mold 220, relative to the neck portion 22 of thepreform 20 which is in a stationary state held by the neck molds 152, ina state where the protruding portion 27 is gripped by the holdingmechanism 230. According to the blow molding mold 200 configured asdescribed above, it is possible to manufacture the container 10 with abent neck having a large inclination angle by the stretch blow molding.Thereby, it is possible to manufacture the container 10 with a bentneck, whose neck portion 12 has a large inclination angle, such that thecontainer 10 has an excellent aesthetic appearance, without consideringthe problems of the direct blow molding.

In the blow molding mold 200 according to the embodiment, the bottommold 220 is configured to be capable of rotating on the plane orthogonalto the opening and closing direction D of the split molds 210 of themold 200 by the rotation mechanism 240. In other words, the bottom mold220 is configured to be capable of rotating along the parting surfaces Cof the split molds 210. When the bottom mold 220 is configured to becapable of rotating on the plane orthogonal to the opening and closingdirection D of the split molds 210, it is possible to reduce a movablewidth necessary for the split molds 210 to move and to save the space,as compared to an aspect where the bottom mold 220 is configured to movein the opening and closing direction D of the split molds 210. Also, athickness of the mold 200 can be reduced, which is advantageous in termsof thermal efficiency.

The blow molding method of the embodiment includes the holding processof gripping the protruding portion 27, which is provided to the bottomportion 24 of the preform 20 independently of the gate portion 26, bythe holding mechanism 230 independently provided to the bottom mold 220of the blow molding mold 200, and the bending process of bending thepreform 20 by rotating the bottom mold 220 which is gripping theprotruding portion 27 relative to the neck portion 22 of the preform 20which is in a stationary state held by the neck molds 152. According tothe blow molding method configured as described above, it is possible tomanufacture the container 10 with a bent neck having a large inclinationangle by a method other than the direct blow molding. Thereby, it ispossible to manufacture the container 10 with a bent neck, whose neckportion 12 has a large inclination angle, such that the container 10 hasan excellent aesthetic appearance, without considering the problems ofthe direct blow molding.

The blow molding method of the embodiment further includes thepreliminary stretching process of stretching the bottom portion 24 ofthe preform 20 toward the bottom mold 220 by the stretch rod 132.According to the blow molding method of the container 10 configured asdescribed above, it is possible to manufacture the container 10 with abent neck having a large inclination angle by the stretch blow molding.

In the embodiment, the protruding portion 27 that is held by the holdingmechanism 230 is provided on a further upper side than the gate portion26 and the diameter thereof is increased to be thick in the widthdirection. Thereby, the holding of the protruding portion 27 by theholding mechanism 230 is stable, and when rotating the bottom mold 220by the rotation mechanism 240, the preform 20 can be favorably preventedfrom separating from the holding mechanism 230. Also, the shape of thepreform can be easily changed by appropriately changing a size of theprotruding portion 27.

In the embodiment, the holding portion 232 is provided independently ofthe bottom mold 220, and is configured to be openable and closable bythe drive member (opening and closing mechanism 234) connected via thelink mechanism at the lower part of the bottom mold 220. Thereby, it ispossible to firmly hold the protruding portion 27 by the holding portion232, and when rotating the bottom mold 220 by the rotation mechanism240, the preform 20 can be favorably prevented from separating from theholding mechanism 230.

In the embodiment, the holding portion 232 of the holding mechanism 230is provided with the claw portion 233. By providing the claw portion233, it is possible to firmly hold the protruding portion 27, and whenrotating the bottom mold 220 by the rotation mechanism 240, the preform20 can be favorably prevented from separating from the holding mechanism230.

Subsequently, an aspect of a resin container according to the embodimentis described with reference to FIG. 7. FIG. 7 depicts an aspect of acontainer 10A that is an aspect of the container with a bent neck havinga large inclination angle. (a) of FIG. 7 depicts the container 10A asseen from an opening-side, (b) of FIG. 7 depicts a front appearance ofthe container 10A, (c) of FIG. 7 depicts a right side appearance of thecontainer 10A, (d) of FIG. 7 is a sectional view of the container 10Ataken along a line E-E, and (e) of FIG. 7 is a sectional view of thecontainer 10A taken along a line F-F.

A basic aspect of the container 10A is similar to the container 10 butdetails are described including possible variations of the inclinationangle X, the size of the container and the like. The container 10A is acontainer made of resin and includes a neck portion 12A having anopening 11A, a body portion 13A formed to be continuous to the neckportion 12A and defining a sidewall part of the container 10A, and abottom portion 14A formed to be continuous to the body portion 13A(refer to the aspect of the container 10 shown in FIG. 1). The bottomportion 14A has an outer edge portion formed to have a horizontalsurface shape and serving as a ground contacting surface, and an upperbottom portion depressed toward the body portion 13A and forming aconcave portion. An inclination angle X between an axis A passingthrough a center of the opening 11A of the neck portion and orthogonalto an opening surface and an axis B extending in a vertical direction ofthe container is within a range of 50° to 80°. The inclination angle Xis preferably within a range of 60° ±5° or 60° to 70°.

As shown in (d) and (e) of FIG. 7, a traverse section in the horizontaldirection of the body portion 13A of the container 10A has asubstantially flat shape so that a neck bending direction can beperceived when the container is gripped and used. In other words, thetraverse section of the body portion 13A of the container 10A has such ashape that a width (a length in the upper and lower direction of thebody portion on the drawing sheet of (d) and (e) of FIG. 7) and a depth(a length in the right and left direction of the body portion on thedrawing sheet of (d) and (e) of FIG. 7) of the body portion 13A aredifferent from each other. From the difference between the width and thedepth, the neck bending direction can be perceived. The container 10A ofFIG. 7 has such a shape that the width is smaller than the depth. Adirection extending in a horizontal diametrical direction of the opening11A may also be referred to as the width direction of the container anda direction in which an axis orthogonal to the opening surface formed bythe opening 11A extends may also be referred to as the depth directionof the container.

The body portion 13A of the container 10A has an upper body portion 13 awhose depth (a width in the right and left direction on the drawingsheet of (b) of FIG. 7) is gradually wider downward and a lower bodyportion 13 b having substantially the same diameter continuing from theupper body portion. The upper body portion 13 a has an inclined portion13 c inclined in a direction substantially orthogonal to the axis A anda curved portion 13 d (shoulder portion) bent to extend in the verticaldirection as it is distant from the neck portion 12A. The body portion13A of the container 10A also has a first vertical surface portion 13 e,second vertical surface portions 13 f and a third vertical surfaceportion 13 g, which are surface-shaped portions extending in thevertical direction. The first vertical surface portion 13 e is asubstantially planar portion positioned at a center of the body portion13A and extending from the bottom portion 14A to the neck portion 12A ofthe container 10A, when the container 10A is seen from the right ((c) ofFIG. 7). The two second vertical surface portions 13 f are present withthe first vertical surface portion 13 e being sandwiched therebetweenand are each a substantially planar portion extending from the bottomportion 14A to the curved portion 13 d, when the container 10A is seenfrom the right ((c) of FIG. 7).

The third vertical surface portion 13 g is a substantially planarportion adjacent to each of the second vertical surface portions 13 f atpositions of the second vertical surface portions 13 f opposite to thefirst vertical surface portion 13 e ((b) of FIG. 7) and extending fromthe bottom portion 14A to the neck portion 12A. The inclined portion 13c, the first vertical surface portion 13 e, the second vertical surfaceportions 13 f and the third vertical surface portion 13 g are provided,so that a sectional shape of the body portion 13A is substantiallyhexagonal ((e) of FIG. 7) in the vicinity of the bottom portion 14A (F-Fsection) and is substantially pentagonal ((d) of FIG. 7) in the vicinityof the neck portion 12A (E-E section). Note that, the first, second andthird vertical surface portions 13 e, 13 f and 13 g mean first, secondand third planar portions extending in the vertical direction,respectively.

An outer surface of the bottom portion 14A of the container 10A (anouter surface of the upper bottom portion) is provided with a projectingportion 215A (projection trace portion) projecting outward from thebottom portion 14A (protruding downward in the vertical direction). Theprojecting portion 215A (projection trace portion) is formed to bewithin a range of a depth of the depression of the bottom portion 14A (adepth of the upper bottom portion). The container 10A can be moldedusing the mold 200 and the preform 20 described in the above embodiment.The projecting portion 215A is a portion formed as the projectingportion 25 of the preform 20 remains after the molding of the container10A. That is, similarly to the projecting portion 25 of the preform 20,at least the protruding portion 27 remains on the projecting portion215A of the container 10A (not shown). The projecting portion 25provided to the preform 20 for molding the container 10A is provided onthe central axis of the preform 20. Thereby, in the mold 200, thepreform can be stretched with the stretch rod 132, so that theprojecting portion 25 can be favorably gripped with the holdingmechanism 230. Therefore, the projecting portion 215A is formed with aconcave portion that is a trace of holding by the holding mechanism 230.The projecting portion 215A of the container 10A formed by bending thepreform 20 may not be provided at the center of the container 10A. Forexample, the projecting portion may be offset (deviate from the center)with respect to the center of the bottom portion of the container 10A.Note that, considering an outer shape of the container 10A, theprojecting portion 215A of the container 10A may be removed by cutting,for example (also in this case, the projecting portion 215A remainsslightly). The container 10A has a height of 10 to 20 cm (preferably, 13cm±3 cm), a width of 2 to 6 cm (preferably, 3±1 cm) and a depth of 3 to10 cm (preferably, 4±1 cm).

As described above, the body portion 13A of the container 10A is formedto have a polygonal shape, so that the rigidity and grip ability of thecontainer 10A are improved. Also, the projecting portion 215A is formedto be within the range of the depth of the depression of the bottomportion 14A, so that the ground contacting stability of the container10A can also be secured.

The present invention is not limited to the embodiments and can bemodified and improved as appropriate. In addition, the materials,shapes, dimensions, numerical values, forms, number, arrangement placesand the like of the respective constitutional elements of theembodiments are arbitrary and are not particularly limited as long asthe present invention can be implemented.

In the embodiment, the container 10 with a bent neck having theinclination angle of about 60° has been described. However, according tothe mold 200 and the blow molding method of the present embodiment, evena container having the inclination angle equal to or larger than 60° orequal to or smaller than 60° can be manufactured by the stretch blowmolding. In addition, the operation of the rotation mechanism 240 mayalso be an operation configured by horizontal movement andlinear/multi-step obliquely upward movement as well as the rotation.

In the embodiments, air has been exemplified as the pressurizing mediumfor blowing the preform 20. However, a gas medium other than air mayalso be used, and a liquid medium such as water can also be used forpressurization.

The subject application is based on Japanese Patent Application No.2018-134579 filed on Jul 7, 2018, the contents of which are incorporatedherein by reference. Also, all references cited therein are entirelyincluded herein.

REFERENCE SIGNS LIST

10: container with a bent neck, 11: opening, 12: neck portion, 13: bodyportion, 14: bottom portion, 20: preform, 21: opening, 22: neck portion,23: body portion, 24: bottom portion, 25: projecting portion, 26: gateportion, 27: protruding portion, 100: blow molding device, 110:injection molding part, 112: injection device, 120: temperatureadjustment part, 130: blow molding part, 132: stretch rod, 140: take-outpart, 150: conveying means, 152: neck mold, 200: blow molding mold, 210:split molds, 220: bottom mold, 230: holding mechanism, 232: holdingportion, 233: claw portion, 234: opening and closing mechanism, 236:accommodation part, 240: rotation mechanism, 242: guide part, 244:guided part

1. A blow molding mold comprising: a bottom mold; a neck mold; a holdingmechanism; and a rotation mechanism, wherein the holding mechanism isindependently provided to the bottom mold and is configured to becapable of gripping a protruding portion provided to a bottom portion ofa preform independently of a gate portion, and wherein the rotationmechanism is configured to be capable of rotating the bottom mold,relative to a neck portion of the preform which is in a stationary stateheld by the neck mold, in a state where the protruding portion isgripped by the holding mechanism.
 2. A blow molding method comprising:gripping a protruding portion, which is provided to a bottom portion ofa preform accommodated in a blow molding mold independently of a gateportion, by a holding mechanism independently provided to a bottom moldof the blow molding mold, in a state where split molds of the blowmolding mold are opened; bending the preform by rotating the bottom moldwhich is gripping the protruding portion relative to a neck portion ofthe preform which is in a stationary state held by a neck mold; andclosing the split molds and stretching the preform by a pressurizingmedium.
 3. The blow molding method according to claim 2, furthercomprising: stretching the bottom portion of the preform toward thebottom mold by a stretch rod before the gripping of the protrudingportion by the holding mechanism.
 4. A container made of resin, thecontainer comprising: a neck portion having an opening; a body portioncontinuous to the neck portion and defining a sidewall part; and abottom portion continuous to the body portion, wherein an inclinationangle between an axis passing through a center of the opening andorthogonal to an opening surface formed by the opening and an axisextending in a vertical direction of the container is equal to or largerthan 50° and equal to or smaller than 80°, and wherein when a directionextending in a horizontal diametrical direction of the opening isreferred to as a width direction of the container and a horizontaldirection orthogonal to the width direction is referred to as a depthdirection of the container, a length in the width direction and a lengthin the depth direction of a horizontal section of the body portion aredifferent from each other.
 5. The container according to claim 4,wherein the bottom portion includes a projecting portion projectingoutward from an outer surface of the bottom portion.
 6. The containeraccording to claim , wherein the body portion includes an upper bodyportion having an inclined surface portion inclined along a directionorthogonal to an axis orthogonal to the opening surface formed by theopening and a lower body portion connected to the upper body portion andextending in the vertical direction, wherein horizontal sections of theupper body portion and the lower body portion have polygonal shapes, andwherein a number of corners of the polygonal shape of the horizontalsection of the upper body portion is smaller than a number of corners ofthe polygonal shape of the horizontal section of the lower body portion.7. The container according to claim 4, wherein the body portion includesan upper body portion having an inclined surface portion inclined alonga direction orthogonal to an axis orthogonal to the opening surfaceformed by the opening and a lower body portion connected to the upperbody portion and extending in the vertical direction, wherein horizontalsections of the upper body portion and the lower body portion havepolygonal shapes, and wherein a number of corners of the polygonal shapeof the horizontal section of the upper body portion is smaller than anumber of corners of the polygonal shape of the horizontal section ofthe lower body portion.